Vibrator motor with self-container lubricant circulator



Dec; 8 1970 J. M. MORRIS 3,546,505

VIBRATOR MOTOR WITH SELF-CONTAINER LUBRICANT CIRCULATOR Filed May 6,1968 3 She ts-Sheet 1 INVENTOR. JOHN M. MORRIS ATTORNEYS J. M. MORRISVIBRATOR MOTOR WITH SELF-CONTAINER LUBRICANT CIRCULATOR Filed May 6;1968 3 Sheets-Sheet 2 FIGS INVENTOR.

JOHN M. MORRIS BYW4M? ATTORNEYS Dec. 8, 1970 J R S 3,546,505

VIBRATOR MOTOR WITH SELF-CONTAINER LUBRICANT CIRCULATOR Filed May e;1968 5 Sheets-Sheet 5 INVENTOR. JOH N M'. MORRIS ATTORNEYS United StatesPatent US. Cl. 31081 8 Claims ABSTRACT OF THE DISCLOSURE This inventionrelates to motors for driving vibratory apparatus and more particularlyto an arrangement in which eccentric weights carried on the motor shaftserve as an impeller of a centrifugal pump for pumping lubricantcontained in a housing surrounding the weights through a circuit thatincludes ball or roller bearings for the purpose of lubricating suchbearings. The invention further employs connecting means, when eccentricweights are mounted at each end of the motor, for equalizing thequantity of lubricating fluid contained in each of the eccentric weighthousings.

BACKGROUND OF THE INVENTION It is common practice to mount the eccentricweights for driving vibratory apparatus directly on the motor shaft andto mount the motor on the member to be vibrated. The size of equipmentthat can be built according to this design is limited by the problem oflubricating the bearings carrying the eccentric weighted shaft.Providing external oil lubrication for the bearings, as is done in largestationary apparatus, is diflicult because of the relative motionbetween the motor frame and any stationary housing surrounding theequipment.

SUMMARY OF THE INVENTION The principal object of this invention is toprovide a self-contained lubricant circulation system for lubricatingthe bearings of a vibrating motor.

An ancillary object of the invention is to subject the oil or otherlubricant to a centrifugal field that is large compared to theacceleration of the motor in its vibratory path to reduce or completelyeliminate any frothing of the oil prior to flowing into the passagesleading to the bearings.

According to the invention the vibratory motor is provided with a sealedend bell serving as a housing for an eccentric weight, as a chamber forcontaining a supply of lubricating fluid, and as the stationary memberof a centrifugal pump. The eccentric weight serves as the impeller ofthe pump and one or more passages are provided in the end bell assemblyleading from the pressurized region of the pump to a bearing supportingthe shaft.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred form of the invention isillustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a side elevation, in simple schematic form, of a vibratoryscreen, agitator, or similar device illustrating a work member to bevibrated by a motor constructed according to the invention.

FIG. 2 is a side elevation with parts broken away to show a preferredform of construction of a self-lubricating motor for a vibratoryapparatus.

FIG. 3 is a vertical section taken substantially along the line 33 ofFIG. 2.

FIG. 4 is a vertical section showing an alternative form of constructionof the end bell that provides the fluid reservoir and housing of thepump.

3,546,505 Patented Dec. 8, 1970 FIG. 5 is a vertical section transverseto the motor axis showing an alternative form of eccentric weight andcooperating passage entrance to increase the output pressure of thepump.

FIG. 6 is a side elevation, with parts broken away, showing a modifiedarrangement of the path of flow of the lubricating fluid.

These specific figures and the accompanying description are intendedmerely to illustrate the invention and not to impose limitations on itsscope.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A vibratory work member 1,which may be a vibratory screen, a vibratory hopper, a vibratory feederor any vibrating body is supported by means of isolation springs 2 froman overhead support indicated by beam fragments 3. A vibratory motor 4constructed according to the invention is rigidly attached to the workmember 1 and is connected through suitable leads, not shown, to a sourceof electrical power. Squirrel cage induction motors are commonlyemployed for this purpose since they can be rigidly constructed so as tobe immune from the effects of the vibratory motion to which they aresubjected.

The motor 4 is shown in greater detail in FIG. 2. As there shown itcomprises a stator 5 that includes an outer shell or frame 6 which maybe provided with cooling fins, a field tructure 7 including the primarywindings and a squirrel cage rotor s supported on a rotor shaft 9.

The motor 4 is provided with at least one end bell 10 that includes aheavy wall 11 in which a ball or roller bearing 12 journaling the shaft9 is mounted. The end bell 10 also includes a cylindrical section orportion 13 terminating in an outwardly directed lip 14 to which an endplate 15 is attached. A first eccentric weight 16 is constructedintegrally with a hub 17 mounted on and keyed to the motor shaft 9. Asecond eccentric weight 18 is adjustably mounted on the hub 17 so thatby varying its angular relation to the first eccentric weight 16 thetotal effective unbalance may be readily adjusted in magnitude.

The heavy wall 11 of the end bell 10, the cylindrical section 13, andthe cover plate 15 form an annular chamber that serves as a reservoirfor a supply of lubricating fluid for the bearing 12. This chamber, atleast in its radially outer portions, has a size and shape thatcorresponds to the space swept through by the eccentric weights 16 and18 as they are revolved by rotation of the shaft 9. The inner wall orsurface of the cylindrical section 13 is smooth so that lubricatingfluid in the chamber may be swept around the periphery by the eccentricweights. It has been observed in this type of construction that thelubricating fluid distributes itself in a substantially uniform annularlayer in the chamber, the layer being slightly thicker on the leadingside of the eccentric weights.

The rotary motion of the lubricating fluid developes a pressure thatcorresponds to the radius of the cylindrical section 13, the angularvelocity of the eccentric weights, the radial thickness of the annularlayer of fluid, and the density of the lubricating fluid. Theoretically,if the cylindrical section has a radius of eighteen inches, the angularveiocity is approximately 700 revolutions per minute and the thicknessof the annular body of lubricating fluid is about a half inch, thepressure corresponds to a column of the fluid approximately 8 to 10 feetin height.

Advantage is taken of this pressure developed in the lubricating fluidto cause it to flow through a duct 20 that leads from a radially outerportion of the annular chamber inwardly and terminates in a distributiongroove 21 formed in the outer race of the bearing 12. Passages 22 leadthe oil or other lubricating fluid from the distribution groove 21 tothe space between the paths of the rollers 23 of the bearing. From thisspace the oil or the lubricating fluid flows axially through the bearingeither directly into the eccentric weight chamber or into a smallchamber 24 between the wall 11 of the end bell and an oil seal 25surrounding the shaft 9 and sealingly attached to the wall 11. A drain26 returns the lubricating fluid collected in the chamber 24 to theeccentric weight chamber.

Referring to FIG. 3, the distribution of the lubricating fluid in thechamber when the motor is running is indicated by the annular body offluid 27 which may have its maximum radial depth at the leading edge 28of the eccentric weights and its minimum radial depth at the trailingedge 29.

Conventional filler plugs 30 and drain plugs 31 are provided tofacilitate adding or changing lubricating fluid.

Preferably the motors for vibratory apparatus are mounted with theshafts horizontal. It occassionally happens, however, in some types ofequipment, that the motor must be mounted with the shaft at an angle tothe horizontal. As an additional feature, recognizing that the oil seal25 may leak, a drain 32, FIG. 2, is provided leading from the spacewithin the stator shell 6 into the eccentric weight chamber at the lowerend of the motor. Furthermore, a connecting passage or tube 33 isprovided to connect a point near the periphery of the eccentric weightchamber at one end of the motor to the corresponding point in a chamberat the other end of the motor. A similar tube 34 is arranged tointerconnect radially inner points of the eccentric weight chambers toprovide an equalizing passage or vent between the chambers. Inoperation, assuming there is a difference in the quantity of lubricatingfluid in the end bells at opposite ends of the motor a differentialpressure is developed between the ends of the connecting passage or tube33 causing a flow of lubricating fluid to equalize the quantity in thetwo chambers. This flow is permitted without change in air pressure inthe chambers by corresponding air flow through the tube 34.

A slightly different form of construction of an improved end bell andhousing is shown in FIG. 4. As shown in this figure, the end bell isformed of a heavy plate suitably attached to the end of the motor stator41. The end bell plate 40 carries a ball or roller bearing 42 thatjournals a motor shaft 43. An eccentric weight 44 mounted on the shaft43 includes a hub 45 on which a second eccentric weight 46 is suitablymounted for angular adjustment relative to the weight 44. Thisconstruction differs from that previously described in that the firsteccentric Weight 44 extends radially further than the second weight 46.A pan-shaped cover 47 is shaped so that at least its marginal portioncorresponds in size and shape to the path or space swept by the radiallyouter portions of the eccentric weight 44. This portion constitutes anannular trough 48 along which the lubricating fluid is driven by theouter portion of the eccentric weight 44.

A suitable duct 49 feeds lubricating fluid from the annular trough 48into the stator 41. The fluid then flows from the stator through thebearing 42 and into the chamber formed within the pan-shaped cover 47.If desired, a suitable partition 50 may be used to separate the hearing42 from the interior of the motor stator 41 and regulate the flow offluid through the bearing. This partition surrounds the motor shaft 43without touching it and forms with the bearing a small chamber throughwhich oil flows to the bearings 42 and back into the cocentric weightchamber to be collected in the trough 48.

In this version as in the first an interconnecting tube 52 connects apoint of the annular chamber of one ed bell 48 with a similar point inthe opposite end bell to provide equalization of the quantity oflubricating fluid in the eccentric weight chambers. In this case a ventor return tube is not necessary since the pressures may equalize by flowof air and oil through the bearings and the opening in the partition 50surrounding shaft 43.

This type of end bell may be used when the motor is mounted at an angleprovided the windings of the motor are provided with an insulation thatis impervious to the lubricating oil. In this case the lubricating fluidfills the otherwise unoccupied space in the interior of the stator 41and flows from such space through the bearings and into the end bells.The pressure developed at the periphery of the lower end bell and therestriction of the partition 50 is suflicient to maintain a flow fromthe stator through the bearings at the upper end of an inclined motor.

As a further modification, the rotor of the motor may be provided withimpeller blades and additional ducts, similar to the duct 20, may beprovided from the stator space to the distribution groove 21. The seal25 may then be omitted and the oil discharged either way from bearing.

In the modification shown in FIG. 5 an eccentric weight 60 is formed sothat its leading edge 61 has greater clearance from the surroundinghousing wall 62 than its trailing edge 63. This difference in clearanceproduces a wedge or sled runner effect to build up pressure between theweight and the housing. This pressure transmits part or all of thecentrifugal force of the rotating eccentric weight 60 directly to thehousing 62 thus relieving the bearings of that load.

An outlet passage 64 for the lubricant (corresponding to passage 20)opens tangentially from the periphery of the housing 62 to convert thevelocity head of the rotating body of lubricating fluid into pressure inthe passage 64 thus tending to increase the circulation of the fluid.The combination of the pressure developed by the centrifugal force isperiodically increased by the sled runner effect each time the weight 60passes the outlet passage 64 thus still further augmenting the flow offluid.

Each of the foregoing circulation methods returns the oil to theeccentric weight chambers near the center of the chamber. While notshown in the drawings, it is desirable to direct the returning oil intothe annular rotating pool with a minimum of agitation to minimize theentrainment of air in the oil. This may be done in any of several ways.One way is to provide a disk attached to the eccentric Weights andlocated between the weights and the bearing, the margin or rim of thedisk being of a size to dip into the annular rotating pool of oil. Themarginal area should be fitted with vanes or fins to ensure rotation ofthe oil in the space between the disk and the motor end plate.

Another way is to provide a small diameter annular cup around the motorshaft and end of the bearing sleeve to catch the oil returning to theeccentric weight chamber. The cup is provided with a radially directeddrain leading into the rotating oil pool.

In either of these arrangements the oil returning to the eccentricweight chamber is slowly accelerated to the shaft speed before flowinginto the annular pool thus avoiding any splashing that occurs if theleading side of the eccentric Weight strikes the incoming stream of oil.

A still further method of returning oil to the rotating pool is to use astationary drain from the bearing leading tangentially, in the directionof eccentric weight movement, into the rotating oil pool. In thisarrangement the incoming oil is accelerated by viscous friction with thero tating pool without impact from the eccentric weights Which wouldcause splashing and foaming.

The lubricating fluid, in addition to lubricating the bearings, may alsobe used as a heat transfer medium to trans fer heat from the statorwindings and rotor of the motor to the housing. A simplified showing ofsuch an arrangement is shown in FIG. 6. In this arrangement eccentricweights 70 drive lubricant fluid through an outlet passage 71 directedinto the space between a stator 72 of the motor and an outside shell 73of the motor. From this space the fluid may flow through gaps 74 leftbetween stator laminations to a rotor 75 of the motor and thence in thegap along the rotor to the spaces at each end of the rotor. From thesespaces the fluid flows through rotor shaft bearings 76 and into theeccentric weight chambers. The lubricating fluid is thus in contact withthe outside shell of the motor and weight assembly as long as it is inthe eccentric weight chambers and during the first part of its paththrough the motor. This provides ample time to cool the fluid prior toits passage past the stator windings and rotor and back through therotor bearings.

In each example the motor stator and attached end bells form a sealedassembly and lubricating fluid in the assembly is pumped through a paththat includes the ball or roller bearings journaling the rotor shaft.

The foregoing specific description is intended to merely illustrate theinvention and not to impose limitations on the claims.

I claim:

1. In a motor for driving vibratory apparatus, in com bination, astator, a rotor having a shaft, an end bell that closes an end of thestator, a shaft bearing mounted in the end bell, a cylindrical extensionthat is concentric with the shaft mounted on the end bell to form a pumpchamber, an end plate included in the extension, said extensioncooperating with the end bell to constitute a centrifugal pump stator,an impeller of substantial mass mounted on the motor shaft within thecylindrical extension for driving any lubricating fluid in thecylindrical extension in a circular path along the periphery of thechamber, said impeller having its center of gravity offset from themotor shaft to constitute an eccentric weight, and a duct in the endbell connecting the periphery of the cylindrical extension to the shaftbearing, whereby lubricating fluid forced to the periphery of thecylindrical extension flows to the bearing.

2. A motor assembly according to claim 1 having sealing means mounted ona wall of the chamber and sur- 6 rounding the shaft to complete theenclosure of the bearing in the chamber.

3. A motor assembly according to claim 1, in which the duct meansextends from the radially outermost portion of the chamber to thebearing.

4. A motor assembly according to claim 1 in which a duct connects aradially outer portion of the chamber of one end bell with acorresponding portion of a similar end bell on the other end of themotor.

5. A motor assembly according to claim 4 having means mounted on theexterior of said chamber in noncontacting relation to said shaft forcollecting lubricating fluid from said bearing and returning it to saidchamber.

6. In a motor assembly according to claim 4, a drain from the interiorof the stator to an end bell chamber.

7. A motor assembly according to claim 1 in which the radial clearancebetween at least one of the eccentric weights and the surroundinghousing varies and has a maximum at the leading edge of the weight.

8. A motor assembly according to claim 1 in which the duct means leadstangentially from the chamber in the end bell.

References Cited UNITED STATES PATENTS 2,688,102 8/1954 Jackson 310-812,854,594 9/1958 Philipovic 31081X 2,857,535 10/1958 Kroeckel et a1310-81 FOREIGN PATENTS 1,100,352 2/1961 Germany 31081 MILTON O.HIRSHFIELD, Primary Examiner M. O. BUDD, Assistant Examiner U.S. Cl.X.R. 31063.90

